[17p trisomy].

Trisomy 17p resulting from a parental translocation t(10;17)(q26.3;p11) was observed in a 22-month-old boy. Analysis of five cases of trisomy 17p from the literature indicates a common malformation pattern: microcephaly, excessive development of the median part of the frontal region, mandibular hypoplasia, permanent opening of the mouth, a high-arched palate, a short, webbed neck, hypotonia, growth retardation, and severe mental retardation. Three abnormal features emphasized by the authors are permanent myosis due to a structural anomaly of the iris; an unusually low blood folate concentration; and an unusual hand configuration, the first four fingers flexed and the little finger extended.